U.S. patent application number 13/237340 was filed with the patent office on 2012-09-20 for deposition mask and method of manufacturing the same.
This patent application is currently assigned to SAMSUNG MOBILE DISPLAY CO., LTD.. Invention is credited to Jung-Woo Ko, Ikunori Kobayashi.
Application Number | 20120234236 13/237340 |
Document ID | / |
Family ID | 46827428 |
Filed Date | 2012-09-20 |
United States Patent
Application |
20120234236 |
Kind Code |
A1 |
Ko; Jung-Woo ; et
al. |
September 20, 2012 |
Deposition Mask and Method of Manufacturing the Same
Abstract
A deposition mask comprises a mask frame having an open window
defined in a center thereof, a first mask sheet placed on the mask
frame and including a plurality of open regions and a separation
region which separates the open regions, and a second mask sheet
placed on the first mask sheet and including a first aperture
portion in a region which contacts the separation region of the
first mask sheet.
Inventors: |
Ko; Jung-Woo; (Yongin-si,
KR) ; Kobayashi; Ikunori; (Seoul, KR) |
Assignee: |
SAMSUNG MOBILE DISPLAY CO.,
LTD.
Yongin-City
KR
|
Family ID: |
46827428 |
Appl. No.: |
13/237340 |
Filed: |
September 20, 2011 |
Current U.S.
Class: |
118/504 ;
156/229; 29/428 |
Current CPC
Class: |
B05B 12/20 20180201;
H01J 11/48 20130101; Y10T 29/49826 20150115; B05C 21/005 20130101;
C23C 14/042 20130101; H01L 51/0011 20130101; H01J 9/24 20130101;
H01L 51/5246 20130101 |
Class at
Publication: |
118/504 ;
156/229; 29/428 |
International
Class: |
B05C 11/00 20060101
B05C011/00; B32B 37/14 20060101 B32B037/14; B23P 11/00 20060101
B23P011/00; B32B 37/02 20060101 B32B037/02 |
Foreign Application Data
Date |
Code |
Application Number |
Mar 15, 2011 |
KR |
10-2011-0023024 |
Claims
1. A deposition mask, comprising: a mask frame having an open
window defined in a center thereof; a first mask sheet placed on
the mask frame and including a plurality of open regions and a
separation region which separates the open regions; and a second
mask sheet placed on the first mask sheet and including a first
aperture portion in a region which contacts the separation region
of the first mask sheet.
2. The deposition mask of claim 1, wherein the second mask sheet
comprises a second aperture portion including a plurality of
apertures which are disposed respectively on the open portions of
the first mask sheet.
3. The deposition mask of claim 2, wherein the first aperture
portion comprises a plurality of apertures, and each aperture of
the first aperture portion has substantially a same shape as each
aperture of the second aperture portion.
4. The deposition mask of claim 3, wherein all apertures, including
the apertures of the first aperture portion and the apertures of
the second aperture portion, are evenly arranged in row and column
directions.
5. The deposition mask of claim 1, wherein the second mask sheet is
divided into a plurality of unit mask sheets.
6. The deposition mask of claim 1, wherein the second mask sheet is
undivided.
7. The deposition mask of claim 1, wherein the first mask sheet is
tensile-welded on the mask frame, and the second mask sheet is
tensile-welded on the first mask sheet.
8. A deposition mask, comprising: a mask frame having an open
window defined in a center thereof; a mask sheet placed on the mask
frame and including a plurality of aperture portions which comprise
a first aperture portion and a second aperture portion; and a
filler filling the first aperture portion.
9. The deposition mask of claim 8, wherein the filler fills an
entirety of the first aperture portion.
10. The deposition mask of claim 8, wherein the second aperture
portion includes a plurality of apertures, wherein the apertures of
the second aperture portion form a plurality of pattern regions,
and the pattern regions are arranged in a matrix form.
11. The deposition mask of claim 10, wherein the first aperture
portion includes a plurality of apertures, and each aperture of the
first aperture portion has substantially a same shape as each
aperture of the second aperture portion.
12. The deposition mask of claim 11, wherein all apertures,
including the apertures of the first aperture portion and the
apertures of the second aperture portion, are evenly arranged in
row and column directions.
13. The deposition mask of claim 8, wherein the mask sheet is
divided into a plurality of unit mask sheets.
14. The deposition mask of claim 8, wherein the mask sheet is
undivided.
15. The deposition mask of claim 8, wherein the mask sheet is
tensile-welded on the mask frame.
16. A method of manufacturing a deposition mask, the method
comprising the steps of: forming a mask frame having an open window
defined in a center thereof; forming a first mask sheet which
includes a plurality of open regions and a separation region
separating the open regions; placing the first mask sheet on the
mask frame; forming a second mask sheet which includes a first
aperture portion; and placing the second mask sheet on the first
mask sheet so that the first aperture portion of the second mask
sheet contacts the separation region of the first mask sheet.
17. The method of claim 16, wherein the second mask sheet includes
a second aperture portion comprising a plurality of apertures which
are disposed respectively on the open portions of the first mask
sheet, and the first aperture portion includes a plurality of
apertures, wherein each aperture of the first aperture portion has
substantially a same shape as each aperture of the second aperture
portion, and all apertures including the apertures of the first
aperture portion and the apertures of the second aperture portion
are evenly arranged in row and column directions.
18. The method of claim 16, wherein the second mask sheet is
divided into a plurality of unit mask sheets.
19. The method of claim 16, wherein the second mask sheet is
undivided.
20. The method of claim 16, wherein the step of placing the first
mask sheet on the mask frame comprises tensile-welding the first
mask sheet on the mask frame, and the step of placing the second
mask sheet on the first mask sheet comprises tensile-welding the
second mask sheet on the first mask sheet.
21. A method of manufacturing a deposition mask, the method
comprising the steps of: forming a mask frame having an open window
defined in a center thereof; forming a mask sheet including a
plurality of aperture portions which comprise a first aperture
portion and a second aperture portion; placing the mask sheet on
the mask frame; and filling the first aperture portion of the mask
sheet with a filler.
22. The method of claim 21, wherein the first aperture portion
includes a plurality of apertures and the second aperture portion
includes a plurality of apertures, wherein the apertures of the
second aperture portion form a plurality of pattern regions which
are arranged in a matrix form, wherein each aperture of the first
aperture portion has substantially a same shape as each aperture of
the second aperture portion, and wherein all apertures including
the apertures of the first aperture portion and the apertures of
the second aperture portion are evenly arranged in row and column
directions.
23. The method of claim 21, wherein the second mask sheet is
divided into a plurality of unit mask sheets.
24. The method of claim 21, wherein the second mask sheet is
undivided.
25. The method of claim 21, wherein the step of placing the mask
sheet on the mask frame comprises tensile-welding the mask sheet on
the mask frame.
26. The method of claim 21, wherein the step of filling the first
aperture portion of the mask sheet with the filler comprises:
coating a photosensitive layer on the second aperture portion of
the mask sheet; forming the filler on the mask sheet coated with
the photosensitive layer; and removing the photosensitive layer
coated on the mask sheet.
27. The method of claim 26, wherein the step of removing the
photosensitive layer coated on the mask sheet comprises performing
exposure and development.
28. The method of claim 21, wherein the filler fills an entirety of
the first aperture portion.
Description
CLAIM OF PRIORITY
[0001] This application makes reference to, incorporates the same
herein, and claims all benefits accruing under 35 U.S.C. .sctn.119
from an application earlier filed in the Korean Intellectual
Property Office on the 15.sup.th of March 2011 and there duly
assigned Serial No. 10-2011-0023024.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention relates to a deposition mask, and more
particularly, to a deposition mask used in the manufacture of a
display device.
[0004] 2. Description of the Related Art
[0005] Electroluminescent elements, which are self-luminous display
elements, are drawing attention as next-generation display elements
due to their wide viewing angle, high contrast, and high response
speed.
[0006] These electroluminescent elements are divided into inorganic
electroluminescent elements and organic electroluminescent elements
according to the material which forms a light-emitting layer.
Organic electroluminescent elements have higher luminance and
response speed than inorganic electroluminescent elements, and are
capable of displaying color images. Due to these advantages,
organic electroluminescent elements are being actively
developed.
[0007] Display devices using organic electroluminescent elements
are manufactured through various deposition processes, and a
deposition mask is used in part of the manufacturing process. A
deposition mask includes a mask frame and a mask sheet.
[0008] In the process of manufacturing a mask sheet, aperture
portions may be formed by chemically etching a rolled metal plate.
However, as the resolution of displays increases, apertures become
smaller, and the gap between the apertures is reduced. Therefore,
it is very difficult to manufacture a high-resolution mask using
the chemical etching method.
[0009] To meet the demand for high-resolution displays,
electroforming may be used in manufacturing a mask sheet. However,
a mask sheet manufactured using electroforming is more deformed by
heat than a conventional mask made of an Invar material. Therefore,
the positions of apertures of the mask sheet may be changed by heat
during a deposition process, and the deformation of the mask sheet
due to heat may create deposition shadows, causing mask
defects.
SUMMARY OF THE INVENTION
[0010] The present invention provides a deposition mask which is
not deformed by heat and a method of manufacturing the deposition
mask.
[0011] However, aspects of the present invention are not restricted
to the ones set forth herein. The above and other aspects of the
present invention will become more apparent to one of ordinary
skill in the art to which the present invention pertains by
referencing the detailed description of the present invention given
below.
[0012] According to an aspect of the present invention, a
deposition mask comprises a mask frame having an open window
defined in a center thereof, a first mask sheet placed on the mask
frame and comprising a plurality of open regions and a separation
region which separates the open regions, and a second mask sheet
placed on the first mask sheet and comprising a first aperture
portion in a region which contacts the separation region of the
first mask sheet.
[0013] According to another aspect of the present invention, a
deposition mask comprises a mask frame having an open window
defined in a center thereof, a mask sheet placed on the mask frame
and comprising a plurality of aperture portions which comprise a
first aperture portion and a second aperture portion, and a filler
filling the first aperture portion.
[0014] According to an aspect of the present invention, a method of
manufacturing a deposition mask comprises forming a mask frame
having an open window defined in a center thereof, forming a first
mask sheet which comprises a plurality of open regions and a
separation region separating the open regions, placing the first
mask sheet on the mask frame, forming a second mask sheet which
comprises a first aperture portion, and placing the second mask
sheet on the first mask sheet so that the first aperture portion of
the second mask sheet contacts the separation region of the first
mask sheet.
[0015] According to another aspect of the present invention, a
method of manufacturing a deposition mask comprises forming a mask
frame having an open window defined in a center thereof, forming a
mask sheet comprising a plurality of aperture portions which
comprise a first aperture portion and a second aperture portion,
placing the mask sheet on the mask frame, and filling the first
aperture portion of the mask sheet with a filler.
BRIEF DESCRIPTION OF THE DRAWINGS
[0016] A more complete appreciation of the invention, and many of
the attendant advantages thereof, will be readily apparent as the
same becomes better understood by reference to the following
detailed description when considered in conjunction with the
accompanying drawings, in which like reference symbols indicate the
same or similar components, wherein:
[0017] FIG. 1 is a perspective view of a mask frame according to an
exemplary embodiment of the present invention;
[0018] FIG. 2 is a perspective view of a first mask sheet according
to an exemplary embodiment of the present invention;
[0019] FIG. 3 is a plan view of the first mask sheet placed on the
mask frame;
[0020] FIG. 4 is a plan view of a second mask sheet according to an
exemplary embodiment of the present invention;
[0021] FIG. 5 is a plan view of a deposition mask according to an
exemplary embodiment of the present invention;
[0022] FIG. 6 is a cross-sectional view, taken along line VI-VI or
FIG. 5, for explaining a deposition process;
[0023] FIG. 7 is a flowchart illustrating a method of manufacturing
a deposition mask according to an exemplary embodiment of the
present invention;
[0024] FIG. 8 is a plan view of a mask sheet placed on a mask frame
according to another exemplary embodiment of the present
invention;
[0025] FIG. 9 is a cross-sectional view taken along the line IX-IX
of FIG. 8;
[0026] FIG. 10 is a plan view of a deposition mask according to
another exemplary embodiment of the present invention;
[0027] FIG. 11 is a cross-sectional view of the deposition
mask;
[0028] FIG. 12 is a flowchart illustrating a method of
manufacturing a deposition mask according to another exemplary
embodiment of the present invention; and
[0029] FIG. 13 is a cross-sectional view of the deposition
mask.
DETAILED DESCRIPTION OF THE INVENTION
[0030] The present invention will now be described more fully with
reference to the accompanying drawings, in which preferred
embodiments of the invention are shown. This invention may,
however, be embodied in different forms and should not be construed
as limited to the embodiments set forth herein. Rather, these
embodiments are provided so that this disclosure will be thorough
and complete, and will fully convey the scope of the invention to
those skilled in the art. The same reference numbers indicate the
same components throughout the specification. In the attached
figures, the thickness of layers and regions is exaggerated for
clarity.
[0031] It will also be understood that, when a layer is referred to
as being "on" another layer or substrate, it can be directly on the
other layer or substrate, or intervening layers may also be
present. In contrast, when an element is referred to as being
"directly on" another element, there are no intervening elements
present.
[0032] FIG. 1 is a perspective view of a mask frame according to an
exemplary embodiment of the present invention, FIG. 2 is a
perspective view of a first mask sheet according to an exemplary
embodiment of the present invention, FIG. 3 is a plan view of the
first mask sheet placed on the mask frame, FIG. 4 is a plan view of
a second mask sheet according to an exemplary embodiment of the
present invention, FIG. 5 is a plan view of a deposition mask
according to an exemplary embodiment of the present invention, and
FIG. 6 is a cross-sectional view, taken along line VI-VI of FIG. 5,
for explaining a deposition process.
[0033] Referring to FIGS. 1 thru 6, the deposition mask according
to the current exemplary embodiment includes the mask frame 100,
the first mask sheet 200 placed on the mask frame 100, and the
second mask sheet 300 placed on the first mask sheet 200.
[0034] The mask frame 100 may have an open window 110 defined in
the center thereof. For example, as shown in FIG. 1, the mask frame
100 may be shaped like a hollow hexagonal prism.
[0035] The first mask sheet 200 may be made of an Invar material
which is an alloy having a low coefficient of thermal
expansion.
[0036] The first mask sheet 200 may include a plurality of open
regions 210 and a separation region 220 which separates the open
regions 210.
[0037] As shown in FIG. 2, the open regions 210 may be arranged in
a matrix form. In some embodiments, when the deposition mask is
used to form an organic film of an organic light-emitting element,
each of the open regions 210 may correspond to one display element.
In this case, the separation region 220 may distinguish different
display elements from each other.
[0038] The first mask sheet 200 may be placed on the mask frame
100. In this case, as shown in FIG. 3, the open regions 210 of the
first mask sheet 200 may be placed on the window 110 of the mask
frame 100.
[0039] The first mask sheet 200 may be fixed onto a surface of the
mask frame 100. For example, the separation region 220 of the first
mask sheet 200 may be tensile-welded onto the mask frame 100.
[0040] The second mask sheet 300 is placed on the first mask sheet
200. The second mask sheet 300 may be fixed onto a surface of the
first mask sheet 200. In some embodiments, the second mask sheet
300 may be tensile-welded onto the first mask sheet 200.
[0041] The second mask sheet 300 may be a metal mask. For example,
the second mask sheet 300 may be formed by electroforming. In some
embodiments, the second mask sheet 300 may be formed by
electroforming metal such as nickel.
[0042] The second mask sheet 300 includes one or more aperture
portions. For example, the second mask sheet 300 may include a
first aperture portion 310 and/or a second aperture portion
320.
[0043] The first aperture portion 310 and the second aperture
portion 320 may be distinguished from each other by a region of the
first mask sheet 200 which is overlapped by the second mask sheet
300. That is, the first aperture portion 310 may overlap the
separation region 220 of the first mask sheet 200, and the second
aperture portion 320 may overlap the open regions 210 of the first
mask sheet 200.
[0044] In some embodiments, each of the first aperture portion 310
and the second aperture portion 320 may include a plurality of
apertures. In some embodiments, all apertures including the
apertures of the first aperture portion 310 and the apertures of
the second aperture portion 320 may be evenly arranged in row and
column directions of the second mask sheet 300.
[0045] The apertures of the first aperture portion 310 may have
substantially the same shape as the apertures of the second
aperture portion 320. In some embodiments, the apertures of the
first aperture portion 310 and the apertures of the second aperture
portion 320 may gradually increase in size toward the first mask
sheet 200 with which the second mask sheet 300 is in contact, as
indicated by reference numeral 330 in FIG. 6. In FIGS. 4 and 5, the
apertures of the first aperture portion 310 and the apertures of
the second aperture portion 320 are square. However, they can also
be circular or slit-shaped.
[0046] As shown in FIG. 6, the second aperture portion 320 of the
second mask sheet 300 is open to the window 110 of the mask frame
100 through the open regions 210 of the first mask sheet 200. On
the other hand, the first aperture portion 310 of the second mask
sheet 300 is not open to the window 110 of the mask frame 100 since
it is placed on the separation region 220 of the first mask sheet
200. Therefore, while the second aperture portion 320 is used as a
passage for depositing an organic material pattern, since an end of
the first aperture portion 310 is closed by the separation region
220 of the first mask sheet 300, the first aperture portion 310
masks a deposition material during a deposition process.
[0047] More specifically, referring to FIG. 6, a source 10 may be
placed under the mask frame 100 during a deposition process. In
this regard, the source 10 may include an organic material used to
form patterns on a substrate. When the organic material in the
source 10 is heated, particles may evaporate and move toward the
substrate. The particles can pass through the open regions 210 of
the first mask sheet 200, but cannot pass through the separation
region 220. The particles passing through the open regions 210 of
the first mask sheet 200 travel through the second aperture portion
320 of the second mask sheet 300, and are then deposited on the
substrate so as to form patterns. Therefore, predetermined patterns
may be formed respectively on a number of display regions of the
substrate equal to the number of the open regions 210.
[0048] The first aperture portion 310 of the second mask sheet 300
may contribute to preventing the deformation of the first mask
sheet 200 and/or the second mask sheet 300. For example, since the
separation region 220 of the first mask sheet 200 does not include
apertures, if the first mask sheet 200 is tensile-welded to the
mask frame 100, the separation region 220 is prone to thermal
deformation since force applied to the separation region 220 per
unit area is strong. However, if the first mask sheet 200 and the
second mask sheet 300 are tensile-welded to each other in a state
where the first aperture portion 310 of the second mask sheet 300
is placed on the separation region 220 of the first mask sheet 200,
the first aperture portion 310 of the second mask sheet 300,
together with the second aperture portion 320 of the second mask
sheet 300, can offset expansion caused by heat generated during a
deposition process.
[0049] If a deposition mask is designed using the mask frame 100,
the first mask sheet 200, and the second mask sheet 300, as in the
current exemplary embodiment, a model of a display can be changed
in a simple way. That is, if a single mask sheet having a plurality
of pattern portions which correspond respectively to the display
regions is used, when the display model is changed, the entire
design of the mask sheet must be changed. However, in the current
exemplary embodiment, when the display model is changed, the second
mask sheet 300 can be used without any modification, and only the
structure of the first mask sheet 200 for distinguishing the
display regions is modified. Therefore, a change in the display
model requires only simple modifications. Accordingly, the cost of
manufacturing a mask sheet based on a change in the display model
can be reduced.
[0050] FIG. 7 is a flowchart illustrating a method of manufacturing
a deposition mask according to an exemplary embodiment of the
present invention.
[0051] In the method of manufacturing a deposition mask according
to the current exemplary embodiment, a mask frame having an open
window defined in the center thereof is formed (operation S100). As
described above, the mask frame may be shaped like a hollow
hexagonal prism.
[0052] Next, a first mask sheet including a plurality of open
regions and a separation region which separates the open regions is
formed (operation S110). As described above, the first mask sheet
may be made of an Invar material, which is an alloy having a low
coefficient of thermal expansion. The open regions of the first
mask sheet may be arranged in a matrix form.
[0053] The first mask sheet is placed on the mask frame (operation
S120). As described above, the open regions of the first mask sheet
may be placed on the window of the mask frame. In some embodiments,
the placing of the first mask sheet on the mask frame may include
tensile-welding the first mask sheet on the mask frame.
[0054] A second mask sheet is formed (operation S130) and is placed
on the first mask sheet (operation S140). As described above, the
second mask sheet may be formed by electroforming, specifically, by
electroforming metal such as nickel. The second mask sheet may
include a first aperture portion in a region which contacts the
separation region of the first mask sheet. The second mask sheet
may further include a second aperture portion which is placed on
the open regions of the first mask sheet. All apertures, including
apertures of the first aperture portion and apertures of the second
aperture portion of the second mask sheet, may be evenly arranged
in row and column directions of the second mask sheet.
[0055] Hereinafter, a deposition mask according to another
exemplary embodiment of the present invention will be
described.
[0056] FIG. 8 is a plan view of a mask sheet placed on a mask frame
according to another exemplary embodiment of the present invention,
FIG. 9 is a cross-sectional view taken along the line IX-IX of FIG.
8, and FIG. 10 is a plan view of a deposition mask according to
another exemplary embodiment of the present invention.
[0057] Referring to FIGS. 8 thru 10, a deposition mask according to
the current exemplary embodiment includes the mask frame 400 and
the mask sheet 500. Specifically, referring to FIGS. 8 and 9, the
deposition mask according to the current exemplary embodiment
includes the mask frame 400, the mask sheet 500 placed on the mask
frame 400, and a filler 520 which fills a first aperture portion
511 of the mask sheet 500.
[0058] The mask frame 400 is substantially identical to the mask
frame 100 according to the exemplary embodiment of FIGS. 1 thru 6,
and thus a repetitive description thereof will be omitted.
[0059] The mask sheet 500 includes a plurality of aperture portions
510. For example, the mask sheet 500 may include the first aperture
portion 511 and/or a second aperture portion 512. The second
aperture portion 512 of the mask frame 500 may correspond to
display regions of a substrate.
[0060] In some embodiments, each of the first aperture portion 510
and the second aperture portion 520 may include a plurality of
apertures. The apertures of the first aperture portion 510 may have
substantially the same shape as the apertures of the second
aperture portion 520. The apertures of the first aperture portion
510 and the apertures of the second aperture portion 520 may have
the same shape as the apertures of the first aperture portion 310
and the apertures of the second aperture portion 320, respectively,
according to the exemplary embodiment of FIGS. 1 thru 6. Therefore,
a detailed description of the shape of the apertures of the first
and second aperture portions 510 and 520, respectively, will be
omitted.
[0061] Referring to FIG. 10, the mask sheet 500 may be placed on
the mask frame 400. In this case, the aperture portions 510 of the
mask sheet 500 may be placed on a window 410 of the mask frame
400.
[0062] All apertures, including the apertures of the first aperture
portion 511 and the apertures of the second aperture portion 512,
may be evenly arranged in row and column directions of the mask
sheet 500. After the first aperture portion 511 is filled, the
second aperture portion 512 may form a plurality of pattern
regions. In some embodiments, the pattern regions may be arranged
in a matrix form.
[0063] The mask sheet 500 may be fixed onto a surface of the mask
frame 400. For example, the mask sheet 500 may be tensile-welded
onto the mask frame 400.
[0064] The mask sheet 500 may be a metal mask. For example, the
mask sheet 500 may be formed by electroforming. In some
embodiments, the mask sheet 500 may be formed by electroforming
metal, such as nickel.
[0065] FIG. 11 is a cross-sectional view of the deposition
mask.
[0066] Referring to FIG. 11, the deposition mask according to the
current exemplary embodiment may include the filler 520 which fills
the first aperture portion 511 of the mask sheet 500. The filler
520 may fill all apertures of the first aperture portion 511. In
this regard, filling apertures with the filler 520 may denote
blocking apertures by closing the apertures with the filler 520. In
some embodiments, an upper end of the filler 520 may be at the same
level as an upper end of the mask sheet 500, and a lower end of the
filler 520 may be at the same level as a lower end of the mask
sheet 500. Furthermore, if the distinction between the filler 520
and the mask sheet 500 around the filler 520 is ignored, the filler
520 and the mask sheet 500 around the filler 520 may have
substantially the same shape as the separation region 220 of the
mask sheet 200 of FIG. 1.
[0067] The filler 520 may be formed by electroforming. In some
embodiments, the filler 520 may be formed by electroforming metal,
such as nickel. In some embodiments, the filler 520 may be made of
the same material as the mask sheet 500.
[0068] As shown in FIG. 11, the second aperture portion 512 of the
mask sheet 500 is open to a window 410 of the mask frame 400. On
the other hand, the first aperture portion 511 of the mask sheet
500 is not open to the window 410 of the mask frame 400 since it is
filled with the filler 520. Therefore, while the second aperture
portion 512 is used as a passage for depositing an organic material
pattern, since an end of the first aperture portion 511 is closed
with the filler 520, the first aperture portion 511 masks
deposition material during a deposition process.
[0069] More specifically, referring to FIG. 11, a source 20 may be
placed above the mask frame 400 during a deposition process. In
this regard, the source 20 may include an organic material used to
form patterns on a substrate. When the organic material in the
source 20 is heated, particles may evaporate and move toward the
substrate. The particles pass through the open second aperture
portion 512 of the mask sheet 500, and are then deposited on the
substrate to form patterns. Therefore, predetermined patterns may
be formed respectively on display regions of the substrate equal in
number to the number of apertures of the second aperture portion
512.
[0070] FIG. 12 is a flowchart illustrating a method of
manufacturing a deposition mask according to another exemplary
embodiment of the present invention, and FIG. 13 is a
cross-sectional view of the deposition mask.
[0071] In the method of manufacturing a deposition mask according
to the current exemplary embodiment, a mask frame having an open
window defined in the center thereof is formed (operation S200). As
described above, the mask frame may be shaped like a hollow
hexagonal prism.
[0072] Next, a mask sheet including a plurality of aperture
portions is formed (operation S210). The aperture portions may
include a first aperture portion and a second aperture portion. As
described above, the mask sheet may be formed by
electroforming.
[0073] The mask sheet is placed on the mask frame (operation S220).
As described above, the aperture portions of the mask sheet may be
placed on the window of the mask frame. In some embodiments, the
placing of the mask sheet on the mask frame may include
tensile-welding the mask sheet on the mask frame.
[0074] The first aperture portion of the mask sheet is filled with
a filler (operation S230). The filling of the first aperture
portion of the mask sheet with the filler will now be described in
greater detail with reference to FIG. 13.
[0075] Referring to FIG. 13, a surface of the mask sheet 500 may
face the window 410 of the mask frame 400 of FIG. 9, and a
photosensitive layer 530 may be coated on regions of the surface of
the mask sheet 500 which correspond respectively to the display
regions. The photosensitive layer 530 may fill the second aperture
portion 512 or may be coated on the second aperture portion
512.
[0076] The filler 520 may be formed on the mask sheet 500 coated
with the photosensitive layer 530. The filler 520 may fill the
first aperture portion 511 of the mask sheet 500. In some
embodiments, the filler 520 may be an electroformed layer.
[0077] Next, the photosensitive layer 530 formed on the mask sheet
500 may be removed. In some embodiments, the photosensitive layer
530 may be removed by exposure and development. When the
photosensitive layer 530 is removed from the mask sheet 500, the
second aperture portion 512 which has been filled with the
photosensitive layer 530 may be open again. The open second
aperture portion 512 may correspond to the display regions of the
substrate.
[0078] As shown in FIG. 13, the first aperture portion 511 of the
mask sheet 500 is open to the window 410 of the mask frame 400 of
FIG. 9. On the other hand, the second aperture portion 512 of the
mask sheet 500 is not open to the window 410 of the mask frame 400
of FIG. 9 since it is filled with the filler 520. Therefore, while
the first aperture portion 511 is used as a passage for depositing
an organic material pattern, since an end of the second aperture
portion 512 is closed with the filler 520, the second aperture
portion 512 masks a deposition material during a deposition
process.
[0079] The first aperture portion 511 of the mask sheet 500 may
contribute to preventing the deformation of the mask sheet 500. For
example, if the mask sheet 500 including only the second aperture
portion 512 which corresponds to the display regions is
tensile-welded to the mask frame 400 of FIG. 9, a region of the
mask sheet 500 in which the second aperture portion 512 is not
formed is prone to thermal deformation since force applied to this
region per unit area is strong. However, if the first aperture
portion 511 is also formed in the mask sheet 500, and if the mask
sheet 500 is then tensile-welded to the mask frame 400, the first
aperture portion 511 of the mask sheet 500, together with the
second aperture portion 512, can offset expansion caused by heat
generated during a deposition process.
[0080] If a deposition mask is designed using the mask frame 400
and the mask sheet 500 as in the current exemplary embodiment, a
model of a display can be changed in a simple way. That is, if a
single mask sheet having a plurality of pattern portions which
correspond respectively to the display regions is used, when the
display model is changed, the entire design of the mask sheet must
be changed. However, in the current exemplary embodiment, when the
display model is changed, the mask sheet 500 can be used without
any modification, and only a filling method of the filler 520 for
distinguishing the display regions is modified. Therefore, a change
in the display model requires only simple modifications.
Accordingly, the cost of manufacturing a mask sheet based on a
change in the display model can be reduced.
[0081] Exemplary embodiments of the present invention provide at
least one of the following advantages.
[0082] A mask sheet can be prevented from being deformed by heat
during a deposition process. Accordingly, the creation of
deposition shadows can be avoided, enabling the precise deposition
of a material at intended locations, and thus realizing the
production of high-resolution display products.
[0083] If resolution is the same, a change in a model of a display
only requires modifications to the structure of an open mask sheet
for distinguishing display regions, or to an aperture portion of
the mask sheet which is filled with a filler.
[0084] Since the a change in the display model requires only simple
modifications, the cost of manufacturing a mask sheet based on a
change in the display model can be reduced.
[0085] However, the effects of the present invention are not
restricted to the ones set forth herein. The above and other
effects of the present invention will become more apparent to one
of ordinary skill in the art to which the present invention
pertains by referencing the claims.
[0086] In concluding the detailed description, those skilled in the
art will appreciate that many variations and modifications can be
made to the preferred embodiments without substantially departing
from the principles of the present invention. Therefore, the
disclosed preferred embodiments of the invention are used in a
generic and descriptive sense only and not for purposes of
limitation.
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